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为探究地震对断层带气体逸出的影响和震后气体地球化学特征随时间的变化,以及地震动力学特征,利用土壤气地球化学方法,于2010年4月14日青海玉树Ms7.1级地震断层甘达村段测量地表破裂特征和震后断层气氡和汞浓度,发现断层带土壤的气氡和汞浓度的平均值分别为9246 Bq/m3和4.2 ng/m3。破裂带中Rn浓度变化幅度大,而Hg的浓度变化较小。断层主滑面附近Rn浓度相对降低,为地表破裂后断层气逃逸所致。泉水气氡观测发现,震前氡浓度增高,表明地震断层活动性增强。因此巴颜喀拉地块向东不均匀挤压,使深部气体沿地震断裂逃逸至地表,这也是造成断层带气氡、汞浓度的增高的原因。
In order to explore the influence of earthquakes on the gas evolution in the fault zone and the temporal variation of gas geochemical characteristics after the earthquake and the characteristics of the earthquake dynamics, a soil gas geochemical method was used to measure the Yushu Ms7.1 earthquake in Qinghai Province on April 14, 2010 Measurements of surface rupture at the Ganda section of the fault and post-earthquake radon and mercury concentrations in the faulted zone found that average concentrations of radon and mercury in the fault zone were 9246 Bq / m3 and 4.2 ng / m3, respectively. In the rupture zone, the concentration of Rn varied greatly, but the concentration of Hg changed little. The Rn concentration near the fault slip surface is relatively lower, which is caused by the escape of fault gas after surface rupture. The observation of spring gas and gas radon showed that the radon concentration increased before the earthquake, indicating that the activity of the earthquake fault was enhanced. As a result, the Bayan Har block is unevenly pressed eastward, causing the deep gas to escape to the surface along the earthquake rupture. This is also the reason for the increase of radon and mercury concentrations in the fault zone.